Conventionally, proposed is a firmware downloading method for downloading firmware program data from a higher-level device to a card reader (for example, refer to Patent Document 1). In the downloading method described in Patent Document 1, a download file including program data is stored in the higher-level device; and if revision information of the download file stored in the higher-level device is not consistent with a response of a revision acquisition command issued by the higher-level device to the card reader, the program data is downloaded from the higher-level device to the card reader.